Daikin error and fault codes for indoor air conditioner units are essential diagnostic tools for troubleshooting and maintaining Daikin air conditioning systems. These codes provide valuable insights into potential issues, helping users and technicians identify and resolve problems efficiently, ensuring optimal performance and comfort of your Daikin air conditioner.
Simple Self-Diagnosis by Malfunction Code For Daikin Indoor Unit
For error codes beginning with A or C, see table below.
For error codes beginning with 6, 7, 8 or 9, find causes here
For error codes beginning with U, find causes here
For error codes beginning with E, F, H, J, L, M or P, find causes here
| Indoor Unit Error Codes and Contents | Supposed causes | Parts affected |
|---|---|---|
| A0 External protection device activated |
External protection device connected to the terminal strip T1-T2 of indoor unit is activated |
SkyAir, VRV, Package |
| A1 Malfunction of indoor unit PCB |
Defective indoor unit PCB External factor (noise etc) |
RA, SkyAir, VRV, Heat reclaim ventilator, Chiller |
| A3 Drain Level Control System Abnormality |
Drain clogging, upward slope, etc Defective drain pump Defective float switch or short circuit connector |
RA, SkyAir, VRV, Heat reclaim ventilator, Fan coil |
| A4 Malfunction of freezing protection |
Shortage of water volume Low water temperature setting Defective water temperature thermistor |
RA, SkyAir, VRV, Package, Chiller, Fan coil |
| A5 High pressure control in heating, freeze-up protection control in cooling |
Clogged air filter of indoor unit and short circuit Defect of indoor unit heat exchanger thermistor |
RA, SkyAir, VRV, Package |
| A6 Malfunction of fan motor |
Broken wires in, short circuit of, or disconnection of connectors from the fan motor harness Defective fan motor Defective indoor unit PCB |
RA, SkyAir, VRV, Package, Heat reclaim ventilator |
| A7 Malfunction of swing flap motor |
Defective swing flap motor Defective indoor unit PCB Defective connection cable Defective airflow direction adjusting flap-cam |
SkyAir, VRV |
| A8 Malfunction of power supply or AC input overcurrent |
Defective power supply voltage Defective connection on signal line Defective wiring |
SkyAir, VRV, Heat reclaim ventilator |
| A9 Malfunction of electronic expansion valve |
Defective electronic expansion valve coil Defective indoor unit PCB Defective relay cables |
SkyAir, VRV, Package, Heat reclaim ventilator. Chiller |
| AA Heater overheat |
26WH is activated | Package, Chiller |
| AF Malfunction of humidifier system |
Humidifier unit (optional accessory) leaking Defective drain piping (upward slope, etc.) Defective indoor unit PCB |
SkyAir, VRV, Heat reclaim ventilator |
| AH Malfunction of dust collector of air cleaner |
Defect of dust collecting element Stained insulator part Defect of high voltage power supply unit Defect of indoor unit PCB |
RA, SkyAir, VRV, Fan coil |
| AJ Malfunction of capacity setting (Indoor unit PCB) |
The capacity setting adaptor was not installed when replacing PCB Defective indoor unit PCB |
SkyAir, VRV, Package |
| C1 Failure of transmission (between indoor unit PCB and sub PCB) |
Defective connection of the connector between indoor unit PCB |
SkyAir, VRV |
| C4 Malfunction of liquid pipe thermistor for heat exchanger |
Defective thermistor for liquid pipe Defective indoor unit PCB Defective connector contact |
RA, SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| C5 Malfunction of gas pipe thermistor for heat exchanger |
Defective thermistor for gas pipe Defective indoor unit PCB Defective connector contact |
RA, VRV, Package, Heat reclaim ventilator, Chiller |
| C6 Malfunction of fan motor sensor or fan control driver |
Defective fan PCB Defective connection of capacity setting adaptor Field setting error |
SkyAir, VRV |
| C7 Front panel driving motor fault |
Defective front panel driving motor Defective limit switch |
RA |
| C9 Malfunction of suction air thermistor |
Defective thermistor for suction air Defective indoor unit PCB Defective connector contact |
RA, SkyAir, VRV, Package, Heat reclaim ventilator, Fan coil |
| CA Malfunction of discharge air thermistor |
Defective thermistor for discharge air Defective indoor unit PCB Defective connector contact |
RA, VRV, Package, Heat reclaim ventilator |
| CC Malfunction of humidity sensor system |
Defective humidity sensor Defective connector contact |
RA, SkyAir, Package |
| CJ Room temperature thermistor in remote controller abnormality |
Defective room temperature thermistor in remote controller Defective remote controller PCB External factor (Noise etc.) |
RA, SkyAir, VRV, Package, Fan coil |
